The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 14, 1990
Filed:
Mar. 28, 1989
Tatsuyoshi Kamohara, Toyota, JP;
Tadashi Sugino, Toyota, JP;
Toshio Suematsu, Toyota, JP;
Satomu Nishimura, Toyota, JP;
Abstract
A warning system for an air-fuel ratio control system for a electronic controlled internal combustion engine, where a basic fuel injection amount is corrected by a feedback correction factor determined by a signal from an air-fuel ratio sensor arranged in an exhaust pipe. An amplitude of the feedback correction factor caused by an acceleration of the engine, where the exhaust from cylinders is not completely mixed, is detected, and a warning can be given when the amplitude of the feedback correction factor is larger than a predetermined value. A malfunction in the air-fuel ratio system occurring in one cylinder can be detected. In a double O.sub.2 sensor system, where a sub-feedback loop is provided for correcting the feedback correction factor in accordance with a signal from the second O.sub.2 sensor, the sub-feedback is stopped when the amplitude of the feedback correction factor is larger than a predetermined value, and a quick and precise detection of a malfunction is obtained by stopping the sub-feedback operation.